This invention is directed to a method of recovering oil from carbonate oil reservoirs. More specifically, this invention is directed to a method of recovering oil from carbonate rock using an “in situ” organic approach.
Known in the art are processes using nutrient stimulation to increase oil production from sandstone oil reservoirs. In contrast, microorganisms needed for the nutrient stimulation process, historically were not known or rarely recovered from oil bearing carbonate rock structures. Moreover, there is no known evidence that any microorganisms seen had or have oil interactive properties.
Based on discoveries in sandstone reservoirs where a change in oil water interaction, as a result of stimulation of oil interactive form of microorganisms, results in more oil released for ultimate recovery, a method for accomplishing the same in carbonate oil reservoirs is needed. More specifically, a method of determining the presence of microorganisms in carbonate reservoirs is needed that also demonstrates that such microorganisms can be converted to hydrophobic form. Such conversion would alter oil water interaction in the carbonate rock structure releasing more oil into the flow channels for production.
An objective of the present invention is to provide a method of increasing oil recovery from carbonate oil reservoirs.
Another objective of the present invention is to provide a method of determining the presence of microorganisms in carbonate reservoirs.
A still further objective of the present invention is to provide a method that alters oil water interaction in carbonate rock structures to release more oil in flow channels.
These and other objectives will be apparent to those skilled in the art based upon the following written description.